How to Make an
Islandora Solution Pack
iCampCA, January 2014
Islandora Solution Pack
● Drupal module, which defines:
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Forms for ingesting objects
Functions for creating derivatives
Themes for rendering objects and data streams
Batches for managing objects
Can define collections
● Typically defines Content Models and
Collection Objects
Drupal Overview
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Hooks
Menus
Permissions
Theming
Docs: http://api.drupal.org/api/drupal/7
Drupal Hooks
● Functions that can be called by other
modules
● Rely on ‘magic’ naming scheme
● hook_do_something()
● mymodule_do_something()
module_invoke_all($hook, $a, $b,
$etc)
● Invokes $hook in all enabled modules
● hook_foo_bar() is implemented as
mymodule_foo_bar()
Example Hook
Implementation
Drupal Menus
● Multiple purpose
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Define routes
Define tabs
Define local actions
Define callbacks
Enforce permissions
Typical Menu Item
Menu Item ‘types’
MENU_NORMAL_ITEM
Shows up as an item in the navigation menu and
breadcrumbs
MENU_CALLBACK
Associates a path with a callback function, used to
render pages and generate non-HTML responses
(JSON for example). No Navigation / Breadcrumbs
MENU_LOCAL_TASK
Typically shows up as a tab
MENU_DEFAULT_LOCAL_TASK
Shows up as the default tab
MENU_LOCAL_ACTION
Typically shows up as a link
Menu Callback Function Arguments
‘page callback' => 'islandora_fits_metadata_display',
'page arguments' => array(2),
http://localhost/drupal7/islandora/object/changeme%
3A10/manage/fits_metadata
Drupal Permissions
● Define who can view/edit content
● Define who can perform actions
hook_permission()
Permissions admin interface
Basics of a Module
.info file
.module file
.install (Mention)
Everything else:
/includes
/theme
/test
/js
/css
/data or /xml
Location of Modules
[drupalroot]/sites/default/modules/
[drupalroot]/sites/all/modules/
[drupalroot]/sites/all/modules/mymodule/
mymodule.info
mymodule.module
Drupal Theming
● All HTML/XML/text sent to browser should
pass through the theming layer
● Also enforces security
● Theming allows local sites to override your
module’s output in template.php, etc.
Theming Components
● Theme functions
● Preprocess functions
● Templates
Theming Functions: hook_theme
theme_mymodule_my_hello
($variables)
Calling Your Theming Hook
$output = theme(‘mymodule_my_hello’, array(‘title’ => ‘This is my title’));
Don’t call theme functions directly aka
theme_table, always use theme(‘theme_name’)
Templates
Preprocess Function
Template: mymodule-hello.tpl.php
<div><?php print $title; ?></div>
Back to Islandora….
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Tuque API
Islandora API
Content models
Collection policies
Islandora hooks
Islandora permissions
Islandora Versioning
● Version numbering scheme
○ Drupal 7 version 1.2
○ Github branch 7.x-release
○ Github branch 7.x
● Always develop against HEAD (7.x)
● Don’t mix and match versions
Tuque
● PHP library that provides an interface to the
Fedora Commons REST API
● Separate from Islandora
● Included by islandora/includes/tuque.inc
Tuque Sample Snippets
https://github.
com/Islandora/islandora/wiki/Build,-Access,Modify-and-Delete-Fedora-objects-with-theTuque-interface
islandora.api.php
● You can find all the hooks defined by
islandora in this file
● Is not functional code, is documentation for
hooks
● Vs. Tuque
○ Tuque is an interface to Fedora Commons
○ Islandora implements Tuque like it would any other
library
islandora.api.php
● Common hooks
○ View / Edit / Purge / Access / Derive
● What the syntax means (CMODEL_PID, etc)
○ CMODEL_PID: Content Model PID
○ DSID: Datastream ID
● islandora.api.php
● islandora_invoke_hook_list()
Lets Start!
Fedora Content Model
Data objects: stored as XML (FOXML)
Datastreams
Internal: stored in the object’s XML
Managed: external to object’s XML
External: linked in the object’s XML
Redirect: simple redirect
Common Islandora Object
Datastreams
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DC (Dublin-Core)
OBJ (Uploaded Content)
TN (Thumbnail)
MODS (Metadata, XML)
RELS-EXT (External Relationships, RDF)
RELS-EXT
Islandora Solution Pack
● Drupal module
● Defines
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forms for ingesting objects
functions for creating derivatives
functions for rendering objects and datastreams
Can define collections
● Typically defines Content Models and
Collection Policies
Define the Content Model
Include it along with any other required objects
via:
hook_islandora_required_objects()
Content Models are expected to define a:
DS_COMPOSITE_MODEL datastream
Collection Policies
A solution pack can define both a Content Model and a
Collection, as well as any number of other objects.
Collections are expected to
● Be of type islandora:collectionCModel
● Include a COLLECTION_POLICY datastream
Displaying the Object
Implementation
Ingest Forms Hooks
● Define your own forms and associate:
○ hook_islandora_xml_form_builder_forms()
○ hook_islandora_xml_form_builder_form_associations()
● Create / Insert steps into the ingest process.
○ hook_islandora_ingest_steps()
○ Image example
Implementation
Derivative Generation
● Using the derivative hook
○ In 7.x HEAD only, not in release 1.2
○ Prior solution packs used islandora_object_ingested
● hook_islandora_derivative()
● hook_CMODEL_PID_islandora_derivative()
Prior to hook_islandora_derivative()
Islandora Permissions
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Gotcha’s
Object exists
Object is of a certain type
Datastream permissions
Access callbacks
XACML can influence this as well.
Access Callbacks
// Permissions (selected list, see islandora.module for rest: https://github.
com/Islandora/islandora/blob/7.x/islandora.module#L84-L362)
define('ISLANDORA_VIEW_OBJECTS', 'view fedora repository objects');
define('ISLANDORA_METADATA_EDIT', 'edit fedora metadata');
define('ISLANDORA_INGEST', 'ingest fedora objects');